"Back in the old days"................Quad reels were the best, but the average Joe (or Jon) could not only not afford the reels, but could not afford the RTR deck. Sure, we could have gotten one, but wives do not appreciate them as much as a washing machine or a new fridge!
That leaves the average Joe's to default to Q8's and QLPs'. I never had huge issues with CD-4, although I do recall frequently having to run the test disc to adjust the little pots on my JVC demodulator (the little silver one), but, if I had a friend over and wanted to demo quad, it was always CD-4 that I used for the demo - mostly James Taylor's "Gorilla". Having Graham Nash and David Crosby in the rears only always got their attention.
I had no love for SQ at all, mostly because the decoders of the day flat ass sucked (compared to my "Gorilla" decode). The Tate was years away, and although QS was better, there were not a lot of QS records, just the ABC Commands, and they too did not approach the "Gorilla" standard.
Q8's were fun and there were actually a lot more titles available in Q8 than any other quad format, so you almost had to go Q8 if you wanted something like "Band of the Run". They lowly Q8 did, however, prove beyond a shadow of a doubt that SQ sucked because listening to a Columbia Q8 vs the Columbia SQ LP was night and day. To this day I am sure this is why then never sold commercial Q4's.
Anyway, even for a sailor on an E-5's salary of the day, once I got out to sea, the money I didn't send home got me a QRX-999 and an AKAI GX-630D-SS, so at that point, when I got home, I was styling!